A typical electronic system includes several components that require different power supply voltages for proper operation. For example, a microprocessor may require a low voltage for a digital core, a higher voltage for input/output operations, another voltage for analog circuitry, and yet another voltage for memory interfaces. The voltage requirements for an electronic system often change when different peripheral devices are to be used. In addition, some electronic systems may require dynamic adjustment and control of these power supply voltages during a power-saving or a sleep mode. An application-specific integrated circuit (ASIC) that is customized for a specific application is often used to implement various custom operational features for providing and controlling power supply voltages such as a turn-on sequence, a turn-off sequence, a single-phase operation, a multi-phase operation, a voltage ramp-up, a voltage ramp-down, a voltage tracking, a voltage positioning, a protection mode threshold, a fault detection, and a fault response.
Power management integrated circuits (ICs) are used to meet the rigorous power supply operational requirements for an electronic system. However, typical power management ICs provide power supply voltages at fixed values, for example, fixed turn-on and turn-off sequences, a static ramp rate, a pre-determined phase operation, and a limited number of protection modes. Due to the limited capability to provide fixed power supply voltages, these power management ICs lack the flexibility and adaptability to accommodate changes in the power supply operational requirements for various target applications. For example, to support multiple voltage rails, existing power management ICs often require a significant number of supporting devices or components such as field effect transistors (FETs). Due to the challenges in the semiconductor process, these field effect transistors are often added as external discrete components of existing power management ICs. The mixed use of FETs and one or more power management IC may take up valuable areas and incur additional cost and time for integration. Hence, there is a need for multi-output power management ICs with integrated field effect transistors and programmable operating characteristics to be adapted to various power applications.